1. Field of the Invention
This invention relates to an access system mounted from an elevated platform along which an elongated mobile tank may be disposed and the access system incorporates extension panel structure for effectively extending the platform outwardly over the near side of the tank and an elongated railing structure supported from the platform for extension therefrom to a position disposed outward of the extension panel structure, extending along and supported from the remote side of the tank. The spacing between the extension panel structure and the railing structure being provided for receiving central tank interior access means carried by the tank therebetween.
Subject matter pertinent to the instant invention is classified in Class 182, subclasses 86, 106, 112, 113, 129, 131, 137 and 179.
2. Description of Related Art
Various different forms of extensions, safety railings, other safety devices and shields including some of the general structural and operational features of the instant invention are disclosed in U.S. Pat. Nos. 862,152, 3,949,834, 4,013,140 and 4,371,056.
The safety equipment disclosed in U.S. Pat. No. 4,013,140 is deemed to be more pertinent to the instant invention than the other above noted patents in that it discloses hinged platform extensions and the steps as well as parallelagram linkage supported railing structure. However, these swingable components are all interconnected for substantially simultaneous swing between raised retracted positions and the lowered extended positions. Although counterbalancing structures are provided to assist in swinging the various components to the raised inoperative positions, such counterbalance structures do not remain effective under a reasonably heavy snow or ice load and the swingable components are therefore very difficult to raise under such a load. With the instant invention the extension panels, access ramp or steps and railing structure are independently swingably supported from the associated platform and different means is provided for swinging each toward the raised inoperative position thereof.